“Weird, destructive, time-warping, overwhelming, alien... fearsomely noisy and rambunctious,” black holes are the bad boys of the universe. And according to Scharf, director of Columbia University’s Astrobiology Center, black holes also play a critical role in shaping the universe. With gravity so great that not even light can escape, massive black holes are invisible. The only way to detect these “lords of gravity” is by looking for the energy from the shock waves created as they gulp down matter. Thanks to X-ray telescopes like the Chandra Space Telescope, astronomers have found energy coming from the hearts of galaxies, including our own Milky Way. After a quick, nontechnical overview of how black holes are created, Scharf discusses how they power galactic dynamics. The most massive grow dim relatively quickly, exhausting their food supply, while a smaller black hole can burn for billions of years, varying from “simmering” beast to “blazing pyre” and back. They cast off ripples of energy, pushing galactic dust and gases outward and slowing stellar formation. Scharf’s explanations are vivid and accessible, evoking the awe of cosmic grandeur in a way that’s as humbling as it is fascinating. Agent: Deirdre Mullane, Mullane Literary Associates. (Aug.)